People cared for at a hospital-based HIV clinic had lower retention in care than people treated in a community clinic, according to a 4-year analysis in Philadelphia [1]. Although frequency of antiretroviral therapy (ART) use was similar among patients at the two settings, hospital-clinic patients were more likely to attain a viral load below 200 copies than the community-clinic group.

Among the many factors that may influence HIV care outcomes, where a patient receives care has received little attention. Researchers at the University of Pennsylvania and other institutions conducted this retrospective cohort study to determine whether care at a hospital-based HIV clinic versus a community clinic affects critical outcomes such as retention in care, starting antiretroviral treatment, and HIV suppression.

This retrospective analysis involved 25 Ryan White-funded HIV clinics in Philadelphia, 13 of them community based and 12 hospital based (including 10 academic centers). Patients considered were at least 18 years old and in care between January 2008 and December 2011. The investigators excluded people in their first year of care and people who received care at more than one clinic. Participants could contribute up to 4 years of data, but the researchers excluded data from people in the year they died.

The study focused on three outcomes: (1) retention in care (defined as two or more visits with an HIV provider separated by at least 90 days in a calendar year), (2) using ART at the last visit in a year, and (3) viral suppression (defined as a viral load below 200 copies at the last viral load measurement in a year). To identify differences in clinical outcomes, the investigators used logistic regression analysis adjusted for clinic setting (hospital or community based), clinic services (case management and clinical pharmacy), and patient characteristics (age, gender, race/ethnicity, HIV transmission route, insurance status, income, and CD4 count).

The number of patients seen rose from 6434 in 2008 to 10,037 in 2011. Retention in care climbed from 79% in 2008 to 85% in 2011, while ART use rose from 83% to 88%, and viral suppression rates jumped from 64% to 78%.

Proportions of people 50 or older rose 30% to 37% from 2008 to 2011. Men accounted for almost two thirds of participants across the study years. About three quarters of participants were black, almost half became infected heterosexually, about one third got HIV during sex between men, and about 15% became infected while injecting drugs. The proportion with a household income below $10,000 fell from 72% in 2008 to 59% in 2011, while the proportion with a CD4 count below 350 dropped from 34% to 27%.

Over the 4 study years, people with HIV attended hospital-based clinics in 61% of patient-years and community-based clinics in 39% of patient-years. Women and people with income above $10,000 were more likely to attend hospital-based clinics, while people with Medicaid, Medicare, or no insurance were more likely to attend community-based clinics.

Proportions of patients using ART were similar in hospital-based clinics and community clinics (87% and 86%). But a lower proportion of hospital patients than community patients were retained in care (82% versus 85%), and a higher proportion of hospital patients attained viral suppression (76% versus 71%). Multivariate analysis confirmed the associations between clinic setting and worse retention but more frequent viral suppression.

The researchers cautioned that their analysis is limited by (1) clinic sample size, (2) limited data on available clinical services, funding, and geographic location, and (3) application to nonurban locations or those outside the Ryan White system. They could not define certain potential outcome differences, such as between teaching hospitals and nonteaching hospitals.

The researchers proposed that "each clinic setting holds lessons for improving different HIV outcomes." And they called for qualitative study to further assess the impact of clinic-level factors on outcomes in people with HIV infection.